Manufacture of red lead.



W. ECKPORD. MANUFACTURE OF RED LEAD.

APPLICATION ILED NOV.27,1909.

Patented NOY. 28, 1911.

UNITED'STATES PATENT OFFICE.

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. PARKER 85 CO. LIMITED, 01: LONDON, ENGLAND.

MANUFACTURE, or BED r Specification of Letters Patent. Pei tented Nov,28, 1911: Application filed November 27, 1909. Serial in. 530,102.-

To all whom it may concern:

Be itknown that I,1.WII LIAM Ecmono, subject of theKing of GreatBritain, residing at Rhyl, in the county of Flint, infthe Principalityof Wales, England, have 1n- -vented certain new and useful Improvementsin or Relating to the Manufacture ofRed Lead, of which the following isa. specification.

my invention for t 1e production of redlead from granulated lead;metallic lead powder, .oxid of lead, massicot or hthai'ge 1s a dryprocess, and yet no appreciable portion of lead oxid can escape into theopen air to contaminate it.

In carrying the invention into effect, the granulated. lead, metalliclead. powder, oxid of lead, massicot or lith'arge, is supplied to amechanical coloring oven preferably without being damped.- andpreferably under a slight suction draft, so that if there be any leakageit will not be outward to the atmos- 'phere. I

After being partly converted into red lead in the coloring oven theproduct. is ground dry in an inelosed mill, with preferablyv a slightinward suction at the inlet of the mill, this grinding being to break upthe powder and enable it to color quickly and more thoroughly. It isagain colored and again ground dry in the same inanner, and againcolored, and so on until the desired red lead is obtained. The soleobject of the slight suction is that if there be any leakage it shall bein-.

ward and not outward.

The.operations' of coloring and grinding are rendered consecutive andcontinuous without any hand manipulation, and the accompanying drawingsshow one'apparatus by which the invention is carried into practicaloperation, in which,

Figure 1 is a diagrammatic view of the appar'atus;'and Fig. 2, adetailed view.

B is a'hopper to which the granulated lead, metallic lead powder, oxidof lead,

: massicot or litharge' is supplied, and which in its, turn supplies theelevator C incased by the casing D, from which there can'be no leakage,outward into the open air, and

. thence by the chute Eto the'pipe F, which ,revolves and-whichdistributes the granulatedlea'd; metallic lead, oxi'd of lead, massicotor litharge, to he bed of the coloring oven G. This oven has a circularbed, and is 3 be following roce'ss'which constitutes hoppers B and:pockets, into which the lead ,oxid'entersbyj i provided with'a verticalshaft H passingthrough the bottom of the oven, and carr ing therevolving arm I, which, carries t e scrapers J. I that they distributethe granulated lead,

metallic lead powder, oxid of lead, massicot' or litharge in the furnaceon'the circularbed' These'scrapers are so arranged after it has beendischargedfrom the pipe F which revolves with the arm I. These scrapersJ on the arm areso setthat they at one side of the. arm cut furrows ofoxi or red lead made'by the scrapersonthe-other side of the arm, and areset at such an angle as to gradually worlrthe oxid from the center tothe outside; The scrapers quBide, or farthest from the center collectand at each' revolution as they pass the hole Kdischarge a portion ofthe now partly colored-red leadinto the screw conveyer L, which feedsthe incased elevator M, thus" liftin the partly colored red lead to thehopperto supply the incased grinder P. The ground redlead is dischargedinto the hopper Q, and-is sup plied to or near the center of-the'coloring" oven R-by the incased-elevator S and chute T. This oven withits arms I, scra rs'J and pipe F, is the sameas the oven and finishedred lead is discharged-at'the'opening U into thedesired receptaclefor-weigh ing or packing into barrels or other vessels, or the grindingand coloring can be repeated again and again as often as required byadding more grindingmills andlovens. ,Whenf' desired. 1 connect thechutes,-elevators, hop pers, ctcetera, with ducts at say pointa -X to asuction fan, so that'no pOivdeificsnsaPe, and any leakage of airshalhbe' inward and not outward.

The pipes Fconvey the lead-oxide! red lead close down on to the'bed ofthe 'oven', and so greatly prevent the raising of dust.

V is a revolvm drum at the bottom 'ofthe which is provided with gravityand the revolution of the druin dc livers the lead oxid from the pocketsin regulated quantities, so that the conveyers C and S cannot et blockedwith the rush of oxid-or red lea The elevatorsC'shownin the drawing areof the bucket type,;but I'do 'not confine myself to using bucket tale---vators, as screw or other conve 'e'rs can-be used instead. Also,-insteado usin the vertical shaft grinder P, any other suitable iosgrinder maybe used, such as one with horiiiio zontal 'or inclinedshafts, or ball grinding mills, or other suitable dry grindingapparatus. When the lead oxid is fed by hand into the hopper B, insteadof automatically from the oxid producer, then suction draft isindispensable at the hopper B.

,Fig. 2 shows an alternative arrangement.

for feeding the powder on to the oven bed F. In this, G is the brick bedof the oven, H the vertical shaft, I the revolving arm, and E the chute.@Th'e pi eF is in this case dispensed with, and a passage V. is formedin the shaft H. This passage, starting in the center of the shaft, isdeflected toward 5 the side and has its orifice near the brick "bed.Thepowder delivered by the chute E passes through ,.this passage and isdischarged on to the oven bed G at or near the center thereof.

The mechanical ovens need not be of the form shown. They may, instead ofthe fixed 'bed and the revolving scraper type, be made with a revolvingbe and fi'xed scraper, or of a revolv ng mclmed cylinder as used forroasting cement. The mechanical ovens. may

be muffled.

' In this process the usual. levigating and separating of the oxid oflead from the metallic particles aredispensed with, no water is used,and thus a greatsaving of heat and of'l'abor is effected, any metalliclead which I may bein the material being converted in the coloring ovenfirst into mon'oxid and then into redlead, without any mechanicalseparation from the other material.-

I declare that what I claim is 2-- 1-. In the manufacture of red lead,subjecting the granulated lead, metallic lead powder, oxid of lead,massicot or litharge in a dry or floury state, to the action of heat 1on the bed of a mechanical coloring oven, and either under atmosphericpressure or under a suction draft or pressure slightly below that of theatmosphere, and grinding the resulting part1 colored red leadin a a drystate under a s ight vacuum or suction, again coloring it on the bed ofa mechanical coloring oven, and againgrinding it, the operations ofalternate coloring and grinding being repeated as often as re uired toobtain the desired red shade of red ead.

2. The process of producing red lead from granulated lead, metallic leadpowder, oxid of lead, massicot-or litha-rge, consisting in subjectingthe material in a dry state to alternate treatments on the beds ofmechanical colorin ovens and dry grindin as often as re uired until thedesired sha e of'red lead is obtained, the lead oxid or partly formedred leadbeing conveyed from the coloring ovens to the grinding deviceswithout exposure to the open air..

In witness whereof,I have hereunto signed my name this 17 day ofNovember 1909, in the presence of two subscribing -witnesses.

G. C. DYMOND, H. WATSON.

